1. Chapter 5 Information Systems in Business: Software

2. Learning Objectives When you finish this chapter, you will:
Understand why managers must keep abreast of software developments.
Recognize the different generations of programming languages and how they differ.
Understand the difference between application software and system software.

3. Learning Objectives
Know the strengths and weaknesses of tailored software vs. off-the-shelf software.
Be able to cite the latest major developments in application and system software.
Recognize characteristics that are important in evaluating packaged software application for business use.

4. Software: Instructions to the Computer
A computer program is a series of instructions to a computer to execute any and all processes.
Computers only “understand” instructions consisting of electrical signals alternating between two states.

5. Programming Languages
Abbreviated forms of instructions that translate into machine language
New programming languages make programming easier for people who are not necessarily hardware experts

6. Programming Languages
Figure 5.1
The evolution of
programming
languages

7. Programming Languages
Machine Languages (ML)
Only languages computers can directly interpret to carry out instructions
String of ‘0s’ and ‘1s’ for a machine language instruction
ML coding: time-consuming and error-prone
ML programmers: concerned with hardware details
Every computer or family of computers has its own ML; each is machine-dependent.

8. Programming Languages
Assembly Languages
More English-like; codes shorter than machine languages
Assembler translates into machine language
Advantages of machine or assembly languages
Programmer in control of hardware
Programs written in low-level languages run more efficiently.

9. Programming Languages
Figure 5.2 The instruction “ADD 2 and 5 and assign the result to variable y” written in different programming languages

10. Programming Languages
Procedural Languages
Third-generation (procedural) languages are more English-like than assembly languages.
Programmers focus on the procedure of the application problem at hand.
Some languages are standardized or portable.
Relatively easy to learn, write, and debug.
FORTRAN, COBOL, BASIC
Requires compiling and linking to test

11. Programming Languages
Fourth Generation Languages (4GL)
4GLs are more English-like than procedural languages.
Programmer only has to select an action without having to specify the action’s formula or procedure.
Easy to learn and use; shorter application development time.
PowerBuilder, FOCUS, NOMAD, and RAMIS

12. Programming Languages
Visual Programming
Languages that let programmers create field windows, scroll-down menus, click buttons, etc., by choosing from a palette
Appropriate code written automatically
Integrated programming environment
Accelerates work
Microsoft’s Visual Basic

13. Programming Languages
Object-Oriented Programming (OOP)
Emphasis on the objects involved in the task, not on the procedure.
An object encapsulates a data set with the code that is used to operate on it.
Standardized programming modules can be reused.
Applications can be rapidly developed with appropriate objects from an object library.

14. Programming Languages
Figure 5.3 Advantages of object-oriented programming (OOP) over procedural languages

15. Programming Languages
Figure 5.4 The object EMPLOYEE

16. Programming Languages
Figure 5.5 Advantages and disadvantages of higher-level programming languages

17. Programming Languages
Application Software vs. System Software
Application: a program developed to address a specific business need; software for development of such programs.
System: programs designed to carry out general routine operations, such as loading, copying, or deleting a file.

18. Application Software Application-specific programs
Programs designed to perform specific jobs
General-purpose programs
Usable for different purposes

19. Application Software Custom-Designed Applications Advantages:
Meeting the organization’s needs exactly
In-house developers are sensitive to the organizational culture
Disadvantages:
High cost
Production schedule subject to long delays
Incompatible with other organizations’ systems

20. Application Software
Figure 5.6 Advantages and disadvantages of custom applications

21. Application Software Packaged Software Advantages:
Low cost
High quality
Vendor support
Immediate availability
Often tested at user sites (alpha sites and beta sites) before the final version is released.

22. Application Software
Figure 5.7 Advantages and disadvantages of packaged software

23. Applications Software
Packaged General Purpose Software
Word processors
Electronic spreadsheets
Database management systems

24. Packaged Software
Figure 5.8 Electronic spreadsheets are powerful tools for (a) tabulation, (b) manipulation, and (c) data analysis.

25. Packaged Software Multimedia
Can handle many different types of data such as text, voice, and image.
Powerful means of communicating.
Uses include education, training, research, and business.

26. Packaged Software Virtual Reality (VR) Mimics sensory reality.
Some sophisticated VR software includes use of goggles, gloves, earphones, and a moving base.
Business use of VR is expected to grow dramatically for design and testing of new products, and for marketing.

27. System Software
Manages computer resources and performs routine tasks not specific to any application
Copying and pasting sections and files
Printing documents
Controlling hardware functions
Allocating memory
Developed to partner with application software

28. System Software Operating Systems (O/S) Most important system software
Developed for a certain microprocessor or microprocessors
Addresses technical details such as registers and RAM addresses.
Plays the role of “traffic cop” or the “boss” of computer resources.

29. System Software
Figure 5.9 The operating system mediates between applications and the computer, and controls peripheral devices.

30. System Software
Figure 5.10 Computers operate on a number of layers, starting from the user interface and moving inward to the hardware.

31. System Software
Figure 5.11 Popular operating systems

32. System Software Operating System Functions Systems Management
User Interface
Memory Allocation
Multitasking, Multiprogramming, and Multiprocessing
Times and Statistics
Increasing Services from O/Ss

33. System Software Compilers and Interpreters Compiler Interpreter
Scans source code and translates into object code
Generates error message and does not compile when an error is found
Allows users to save programs in object code
Interpreter
Checks one statement at a times
Converts into object code and executes

34. System Software
Figure 5.12 A compiler converts higher-level language code (source code) into machine language (object code), which the computer can process.

35. System Software Data Communication Programs
Controls and supports data communication activities in a network
Setting up rules that govern transmission and reception of data
Connecting and disconnecting communication links
Assigning priorities among terminals in a network
Detecting and correcting transmission errors

36. System Software Proprietary vs. Open Source
Proprietary O/S: limited to using applications compatible with it
Open O/S: compatible with virtually all applications.
Completely open O/S does not exist
Some O/Ss (e.g., Unix) are said to be nonproprietary, but it is still impossible to run many applications on different versions of such O/Ss.

37. Considerations in Purchasing Software
Figure 5.13 Sample software evaluation form

38. Considerations in Purchasing Software
Figure 5.14 Sample results of software evaluation (5 is the highest score.)